One hundred three patients with bladder cancer underwent balloon-occluded arterial infusion. In 66 patients whose therapeutic effects could be evaluated by endoscope, CT and angiography, the anti-tumor effective rate (CR + PR) was 78.8%. In 15 patients who were not treated by trans-urethral resection or total cystectomy but BOAI, one-year cumulative survival rate was 46.7% and the two-year rate 13.3%. The longest survival period after BOAI was 7 years and 8 months. 133Xe activity of bladder tumor area in BOAI was 6.60 times higher than in simple arterial infusion. BOAI was thought to be a promising conservative treatment in advanced bladder cancer.